Grown-up Congenital Heart Disease (GUCH): Difference between revisions

In large defects, defined as those with diameters equal or greater than 75% of the aortic annulus, there is no restriction of blood flow across the septum, leading to equal pressures in both right and left ventricle. The large left to right shunt initially only leads to excessive volume overload in the pulmonary arteries, left atrium and left ventricle. The chronic pressure and volume overload combined with the increase flow leads to irreversible changes of the pulmonary vasculature, which results in an increase in pulmonary vascular resistance. This increase in resistance leads to a reversal of the shunt through the VSD causing right to left shunt with cyanosis (Eisenmenger syndrome).